Battery bank size - small boat, big trip

[Nadezhda]

couple of 100ah will be plenty and a separate one for your starter motor

[roverhi]

Have cruised with 220ah of GC batteries with similar electrical drain as you have. The first cruise had only engine alternator to charge the batteries. On recent sail to Hawaii had 12 days of heavy overcast. Batteries were down to 12.2 volts by the time the sun came out. Have 240 watts of solar in two panels wired in series. Probably didn't get optimum output out of the panels as the mast shaded portions of the panels by 2 in the afternoon sailing into the sun. Ran a Garmin 3208 plotter, AIS and the Raymarine X5 autopilot on stand by for the compass 24/7. Also used the Ham radio for a few hours daily downloading GRIBS and checking in on the MM net. All lights are LED.

Am presently adding refrigeration and planning on a couple more more GC batteries for 440ah total.

Think you'll do fine with 220ah of batteries. Remember, the more amps you have, the longer it takes to charge them back up.

[hamburking]

I had a C&C25 with NO charging at all (solar panel was stolen...thank you very much marina security!). Pull start outboard (no charge circuit). All the same stuff you mention...led lights, autohelm, radio, plus we had a portable DVD player.

Originally had 2 type 24 batteries. One died. Got rid of it. I would charge the one battery overnight at the dock. It was then good for a solid week of cruising using all our lights, authelm (all day), etc. After a week (seven days), it would be down to 12.0 - 12.1 volts.

With your excellent solar panel, you could likely have a single type 24 battery. If you are on a really tight budget, or have no space, it would likely be fine. Two would be better. The type 24, deep cycle, lead acid battery is about the cheapest you'll find.

As others have said, separate battery for engine starting.

[jamhass]

Couple of thoughts

1. Computers, especially older ones can use much more power than we often realize, even more if they must be charged via an inverter. Make sure you have appropriate 12v power supplies/chargers.

2. Where will you be cruising? Even in the sunny waters here in the Sea of Cortez our solar puts out only a fraction of its 250 watts MOST of the time. Consider the Honda 2000 to reduce hours on the main engine. If you find you don't need it, you can always sell it.

[lockie]

I suggest you also consider upgrading the regulator for your engine alternator with a Baldar, Sterling etc. These make a huge difference to how much charge your batteries will get when you run the engine, for a couple of hundred bucks.

With your 225W solar panel, dedicated start battery, and a decent alternator regulator, just forget the petrol generator. You won't need it, it will take up valuable space, and you'll have the big hassle of carrying extra petrol safely on a small boat.

Cheers, Graeme

[goat]

Originally Posted by anacapaisland42

I strongly recommend an automatic electric bilge pump
Bill

What he said ^

It's there to protect you when you're not on the boat. Set it high enough that it won't turn on unless you're taking on a lot of water, if you're worried about battery use.

goat